Conventional vehicle restraint or seat belt systems combining a lap belt and an upper torso or shoulder belt to restrain an occupant or passenger in a vehicle are well known and are standard OEM equipment on most passenger cars. However, such OEM restraint systems do not provide adequate protection for a child under the approximate age of 8 years, for reasons such as the following:                The seatbelts are not sufficiently snug on a small body and do not comprise, provide or impose a sufficient downwards force.        The shoulder belt could rub against the child's neck.        Most children are not mature enough to be seated in a seat designated for adults.        
The National Highway Traffic Safety Administration (NHTSA) recommends that rear-facing seats be used in the back seat for children from the age of birth to at least 1 year old and at least 20 pounds. Forward-facing toddler seats are to be used in the back seat for children from age 1 and 20 pounds to about age 4 and 40 pounds. Booster seats are to be used in back seat for children from about age 4 to until they are at least 8 years old, unless they are 4′9″ tall. Safety seat belts are to be used for children at age 8 and older or taller than 4′9″. All children age 12 and under should ride in the back seat of a vehicle.
Booster seats are used because safety seat belts in vehicles are not designed for children. Beginning at about 4 years of age, many children have outgrown toddler seats but still they are too small for adult-sized vehicle safety seat belts. A booster seat raises the child up so that a safety seat belt properly fits—and can better protect the child. The NTHSA recommends that children who have outgrown child safety seats should be properly restrained in booster seats (which boost a child to a height where the adult lap-and-shoulder belts fit properly) until they are at least 8 years old, unless they are 4′9″ tall.
Nonetheless, well before children are 8 years old or 4′9″ tall, parents start encountering resistance from their “big” children against the use of the booster seat, a feature seemingly associated with being considered still a “small kid” or child. At the same time, by that age, children are well accustomed to carrying a back-pack for extended time throughout their day, and are very comfortable with wearing a backpack's shoulder straps wrapped tightly around their upper body.
From the point of view of a child who is not yet 8 years old or 4′9″ tall, it would be very desirable if a vehicle could be fitted with an effective and regulation-compliant restraint system that does away with the booster seat and uses padded shoulder straps modeled after a backpack's shoulder straps. It would also be desirable for such restraint system to be easy to install in a variety of vehicle and seat configurations, comfortable for the child, easy to adjust for the child's size, and easy to remove when not needed. Despite this long-felt need in the market, it does not appear that such restraint systems exist to meet the above-described user requirements.